The present invention relates to a package having a multilayer film disposed around a layered coil of filament strands. More particularly, the present invention relates to a package having a multilayer film comprising an ionomer, disposed around a layered coil of filament strands such that the ionomer contacts the layered coil of filament strands.
Packages having a layered coil of filament strands, in the form of a pirn, are removed from a package by the uncoiling of the layered filament strands from the inside of the pirn, until all of the strand material has been removed from the package. Such packaged pirns of, for example, glass fiber strands, are used in the manufacture of reinforced pipe, reinforced storage tanks, insulating jackets, glass fiber sheet, insulation for wiring, etc.
A problem in the removal of the layered filament strands from a pirn of strand material in a package is that as more of the strand material is removed from the inside of the pirn to the outside of the pirn, the outer layers of strands can become unsupported and collapse, causing the remaining portion of the strand to become tangled. This can interrupt production processes and cause waste of the entangled strand material. Several approaches to solving this problem are known.
One approach has been the application of adhesive materials to the interior of a package surrounding the sides of the pirn, so that the adhesive secures the outer strand layer to the package, thereby preventing the strand material from falling inwardly and becoming entangled. Yet another approach is to allow an outer sheet or film surrounding the strands to controllably collapse. Still another approach is to use a film around the strands that can be induced to undergo a high degree of shrinkage, thereby causing an intimate physical relationship between the outer strands and the sheet material, which provides support for the outer strands.
Another approach includes the use of a relatively thick sheet of an ionic copolymer, also referred to herein as an xe2x80x9cionomerxe2x80x9d, disposed around a wound strand. As the strand is removed from the wound strand, the uncoiling of the strand causes a wiping of the strand along the package, which in turn induces an electrostatic charge between the ionomer sheet and the strand coils that are in contact with the ionomer sheet. The induced charge forms an attraction between the strand and sheet, which is sufficiently strong to hold strands against the sheet and prevent their collapse, in spite of the weight of the coiled strand. However, this type of packaging has heretofore been expensive because a relatively large amount of ionomer resin is required to make the relatively thick ionomer sheet. Furthermore, the packaging of a pirn of wound strand material is cumbersome because a shrunken bag is generally used to hold the ionomer sheet against the outer surface of the pirn, adding to the complexity of the packaging. A need remains for methods of packaging pirns of strand material, having acceptable cost and minimizing waste by avoiding tangling and loss of the strand material. A need also remains for new and/or improved packages for strand material. The present invention is directed to these, as well as other, important ends.
One aspect of the invention is a package comprising a layered coil of filament strands and a multilayer film disposed around the layered coil of filament strands. The coil has an outer surface comprising a bottom surface region, a side surface region and a top surface region. The multilayer film comprises a first outer layer forming an inside layer of the multilayer film, the first outer layer comprising ionomer resin, a second outer layer forming an outside layer of the multilayer film, the second outer layer comprising at least one member selected from the group consisting of ethylene/vinyl acetate copolymer, polyvinylidene chloride, polyethylene homopolymer, polypropylene homopolymer, ethylene/alpha-olefin copolymer, polyvinyl chloride, polyamide, polyester, and polystyrene, and at least one inner layer, at least one of the at least one inner layer being a bulk layer and comprising cross-linked ethylene/vinyl acetate copolymer with a thickness of at least about 0.5 mils. The first outer layer comprising ionomer resin is in direct contact with the side surface region of the layered coil of filaments. The multilayer film is in the form of a sleeve and the sleeve has a volume of from about 2.0xc3x97 to 1.01xc3x97 of a total volume of the coil of filament strands before shrinkage.
Another aspect of the invention is a package comprising a layered coil of filament and a sleeve surrounding, and in direct contact with, the layered coil of filament strands. The layered coil has an outer surface comprising a bottom surface region, a side surface region, and a top surface region. The sleeve comprises a multilayer film, wherein the multilayer film comprises:
(a) a first outer layer forming an inside layer of the package, comprising ionomer in an amount of from about 50 to 100 weight percent, based on the weight of the first outside layer, said first outer layer having a thickness of from at least about 0.05 mils;
(b) a second outer layer forming an outside layer of the package, comprising a blend of 50 to 99 weight percent ethylene/vinyl acetate copolymer and 1 to 50 weight percent olefin polymer, based on the weight of the second outer layer, said second outer layer having a thickness of at least about 0.01 mils;
(c) a first inner layer which is between the first outer layer and the second outer layer, the first inner layer comprising ethylene/vinyl acetate copolymer in an amount of from about 50 to 100 weight percent, based on the weight of the first inner layer, the first inner layer having a thickness of at least about 0.5 mils;
(d) a second inner layer which is between the first inner layer and the second outer layer, the second inner layer comprising, in an amount of at least about 50 weight percent based on the weight of the second inner layer, at least one member selected from the group consisting of ethylene/vinyl alcohol copolymer and polyvinylidene chloride, the second inner layer having a thickness of at least about 0.05 mils; and
(e) a third inner layer which is between the second inner layer and the second outer layer, the third inner layer comprising ethylene/vinyl acetate copolymer in an amount of from about 50 to 100 weight percent, based on the weight of the third inner layer, the third inner layer having a thickness of at least about 0.5 mils.
Another aspect of the invention is a package comprising a layered coil of filament strands and a sleeve surrounding, and in direct contact with, the layered coil of filament strands. The coil has an outer surface comprising a bottom surface region, a side surface region, and a top surface region. The sleeve comprises a multilayer film, wherein the multilayer film comprises:
(a) a first outer layer forming an inside layer of the package, comprising ionomer in an amount of from about 50 to 100 weight percent, based on the weight of the first outside layer, said first outer layer having a thickness of at least about 0.05 mils;
(b) a second outer layer forming an outside layer of the package, comprising a blend of 50 to 99 weight percent ethylene/vinyl acetate copolymer and 1 to 50 weight percent olefin polymer, based on the weight of the second outer layer, said second outer layer having a thickness of at least about 0.01 mils;
(c) a first inner layer which is between the first outer layer and the second outer layer, the first inner layer comprising ethylene/vinyl acetate copolymer in an amount of from about 50 to 100 weight percent, based on the weight of the first inner layer, the first inner layer having a thickness of at least about 0.5 mils;
(d) a second inner layer which is between the first inner layer and the second outer layer, the second inner layer comprising ethylene/vinyl acetate copolymer in an amount of from about 50 to 100 weight percent, based on the weight of the second inner layer, the second inner layer having a thickness of at least about 0.5 mils.